wafts awfts wfats fwats afwts fawts watfs awtfs wtafs twafs atwfs tawfs wftas fwtas wtfas twfas ftwas tfwas aftws fatws atfws tafws ftaws tfaws wafst awfst wfast fwast afwst fawst wasft awsft wsaft swaft aswft sawft wfsat fwsat wsfat swfat fswat sfwat afswt faswt asfwt safwt fsawt sfawt watsf awtsf wtasf twasf atwsf tawsf wastf awstf wsatf swatf aswtf sawtf wtsaf twsaf wstaf swtaf tswaf stwaf atswf taswf astwf satwf tsawf stawf wftsa fwtsa wtfsa twfsa ftwsa tfwsa wfsta fwsta wsfta swfta fswta sfwta wtsfa twsfa wstfa swtfa tswfa stwfa ftswa tfswa fstwa sftwa tsfwa stfwa aftsw fatsw atfsw tafsw ftasw tfasw afstw fastw asftw saftw fsatw sfatw atsfw tasfw astfw satfw tsafw stafw ftsaw tfsaw fstaw sftaw tsfaw stfaw
Note: these 'words' (valid or invalid) are all the permutations of the word wafts. These words are obtained by scrambling the letters in wafts.