Would these prisms work for a diy anamorphic lens?

I can't say for sure, but I think those lenses are too small. The light beam out of a HT projector will bee too large to fit through the lenses.

They don't work, because i've tried it out
We use these prisms in our laboratories to transform the elliptic laser beam coming out from the laser diode into a circular beam. Note that there is no need for a large aperture and CA or astigmatism correction in these applications. For that purpose, the prisms work great. But, as HopefulFred already said, they are simply too small for the use in home theaters.

So, don't waste your money on these prisms.