sparks psarks saprks asprks pasrks apsrks spraks psraks srpaks rspaks prsaks rpsaks sarpks asrpks srapks rsapks arspks raspks parsks aprsks prasks rpasks arpsks rapsks spakrs psakrs sapkrs aspkrs paskrs apskrs spkars pskars skpars kspars pksars kpsars sakprs askprs skaprs ksaprs aksprs kasprs paksrs apksrs pkasrs kpasrs akpsrs kapsrs sprkas psrkas srpkas rspkas prskas rpskas spkras pskras skpras kspras pksras kpsras srkpas rskpas skrpas ksrpas rkspas krspas prksas rpksas pkrsas kprsas rkpsas krpsas sarkps asrkps srakps rsakps arskps raskps sakrps askrps skarps ksarps aksrps kasrps srkaps rskaps skraps ksraps rksaps krsaps arksps raksps akrsps karsps rkasps krasps parkss aprkss prakss rpakss arpkss rapkss pakrss apkrss pkarss kparss akprss kaprss prkass rpkass pkrass kprass rkpass krpass arkpss rakpss akrpss karpss rkapss krapss sparsk psarsk saprsk asprsk pasrsk apsrsk sprask psrask srpask rspask prsask rpsask sarpsk asrpsk srapsk rsapsk arspsk raspsk parssk aprssk prassk rpassk arpssk rapssk spasrk psasrk sapsrk aspsrk passrk apssrk spsark pssark sspark sspark pssark spsark sasprk assprk ssaprk ssaprk assprk sasprk passrk apssrk psasrk spasrk aspsrk sapsrk sprsak psrsak srpsak rspsak prssak rpssak spsrak pssrak ssprak ssprak pssrak spsrak srspak rsspak ssrpak ssrpak rsspak srspak prssak rpssak psrsak sprsak rspsak srpsak sarspk asrspk sraspk rsaspk arsspk rasspk sasrpk assrpk ssarpk ssarpk assrpk sasrpk srsapk rssapk ssrapk ssrapk rssapk srsapk arsspk rasspk asrspk sarspk rsaspk sraspk parssk aprssk prassk rpassk arpssk rapssk pasrsk apsrsk psarsk sparsk asprsk saprsk prsask rpsask psrask sprask rspask srpask arspsk raspsk asrpsk sarpsk rsapsk srapsk spaksr psaksr sapksr aspksr pasksr apsksr spkasr pskasr skpasr kspasr pksasr kpsasr sakpsr askpsr skapsr ksapsr akspsr kaspsr pakssr apkssr pkassr kpassr akpssr kapssr spaskr psaskr sapskr aspskr passkr apsskr spsakr pssakr sspakr sspakr pssakr spsakr saspkr asspkr ssapkr ssapkr asspkr saspkr passkr apsskr psaskr spaskr aspskr sapskr spksar psksar skpsar kspsar pkssar kpssar spskar psskar sspkar sspkar psskar spskar skspar ksspar sskpar sskpar ksspar skspar pkssar kpssar psksar spksar kspsar skpsar sakspr askspr skaspr ksaspr aksspr kasspr saskpr asskpr ssakpr ssakpr asskpr saskpr sksapr kssapr sskapr sskapr kssapr sksapr aksspr kasspr askspr sakspr ksaspr skaspr pakssr apkssr pkassr kpassr akpssr kapssr pasksr apsksr psaksr spaksr aspksr sapksr pksasr kpsasr pskasr spkasr kspasr skpasr akspsr kaspsr askpsr sakpsr ksapsr skapsr sprksa psrksa srpksa rspksa prsksa rpsksa spkrsa pskrsa skprsa ksprsa pksrsa kpsrsa srkpsa rskpsa skrpsa ksrpsa rkspsa krspsa prkssa rpkssa pkrssa kprssa rkpssa krpssa sprska psrska srpska rspska prsska rpsska spsrka pssrka ssprka ssprka pssrka spsrka srspka rsspka ssrpka ssrpka rsspka srspka prsska rpsska psrska sprska rspska srpska spksra psksra skpsra kspsra pkssra kpssra spskra psskra sspkra sspkra psskra spskra skspra ksspra sskpra sskpra ksspra skspra pkssra kpssra psksra spksra kspsra skpsra srkspa rskspa skrspa ksrspa rksspa krsspa srskpa rsskpa ssrkpa ssrkpa rsskpa srskpa sksrpa kssrpa sskrpa sskrpa kssrpa sksrpa rksspa krsspa rskspa srkspa ksrspa skrspa prkssa rpkssa pkrssa kprssa rkpssa krpssa prsksa rpsksa psrksa sprksa rspksa srpksa pksrsa kpsrsa pskrsa spkrsa ksprsa skprsa rkspsa krspsa rskpsa srkpsa ksrpsa skrpsa sarksp asrksp sraksp rsaksp arsksp rasksp sakrsp askrsp skarsp ksarsp aksrsp kasrsp srkasp rskasp skrasp ksrasp rksasp krsasp arkssp rakssp akrssp karssp rkassp krassp sarskp asrskp sraskp rsaskp arsskp rasskp sasrkp assrkp ssarkp ssarkp assrkp sasrkp srsakp rssakp ssrakp ssrakp rssakp srsakp arsskp rasskp asrskp sarskp rsaskp sraskp saksrp asksrp skasrp ksasrp akssrp kassrp saskrp asskrp ssakrp ssakrp asskrp saskrp sksarp kssarp sskarp sskarp kssarp sksarp akssrp kassrp asksrp saksrp ksasrp skasrp srksap rsksap skrsap ksrsap rkssap krssap srskap rsskap ssrkap ssrkap rsskap srskap sksrap kssrap sskrap sskrap kssrap sksrap rkssap krssap rsksap srksap ksrsap skrsap arkssp rakssp akrssp karssp rkassp krassp arsksp rasksp asrksp sarksp rsaksp sraksp aksrsp kasrsp askrsp sakrsp ksarsp skarsp rksasp krsasp rskasp srkasp ksrasp skrasp parkss aprkss prakss rpakss arpkss rapkss pakrss apkrss pkarss kparss akprss kaprss prkass rpkass pkrass kprass rkpass krpass arkpss rakpss akrpss karpss rkapss krapss parsks aprsks prasks rpasks arpsks rapsks pasrks apsrks psarks sparks asprks saprks prsaks rpsaks psraks spraks rspaks srpaks arspks raspks asrpks sarpks rsapks srapks paksrs apksrs pkasrs kpasrs akpsrs kapsrs paskrs apskrs psakrs spakrs aspkrs sapkrs pksars kpsars pskars spkars kspars skpars aksprs kasprs askprs sakprs ksaprs skaprs prksas rpksas pkrsas kprsas rkpsas krpsas prskas rpskas psrkas sprkas rspkas srpkas pksras kpsras pskras spkras kspras skpras rkspas krspas rskpas srkpas ksrpas skrpas arksps raksps akrsps karsps rkasps krasps arskps raskps asrkps sarkps rsakps srakps aksrps kasrps askrps sakrps ksarps skarps rksaps krsaps rskaps srkaps ksraps skraps
Note: these 'words' (valid or invalid) are all the permutations of the word sparks. These words are obtained by scrambling the letters in sparks.