can you thow flowering plants back into veg?

i have a couple plants with 6 plus weeks to go and was wondering if i could throw them back into 18 or 20 hrs of light, reason being is one of the plants came from a buddy full of mites and i didn`t know till the leaves were 1/2 trashed. now i don`t have much left for leaves other than what`s on the bud and i want to keep these going! it`s killer smoke and i don`t want to lose the strain. was thinking that maybe if i re veg i can grow some leaves and maybe take a couple clones. will it work??

sure, but it will take a long time and you might want to cut the buds off first and start over with new soil and whatever is left from the original plant.