yeah, go for it man. Earthworms are awesome for fish. If your fish refuses to eat, just entice them with earthworms, thats what i did with mine when they went a couple of weeks without eating.
Yeah, they love them - just don't feed them very often. Use them as an occasional treat, earthworms are high in protein and will make your fish fat if they get too many.
my friend, who's a RD freak, feeds his 1-2 every 2-3 days and it grew to almost 14" wth in the yr. Was fiesty as hell too and only had a much older pleco in with it.