Woman here with a penis and hands:

It could be good? It seems to be vibrating, which my hands can't do and I enjoy from my sex toys. Then the obvious in and out motion, as long as everything is lubricated, seems pleasurable too. Idk if you'd be able to use lube for a sperm donation though, I was told not to when I was getting my swimmers frozen. Maybe it'd be fine without lube though, if its somewhat flexy and not too tight.

Hope this helps.