Preseed safe to... umm swallow?

So in general my DH needs a good amount of oral stimulation. About to start? oral. Switching positions? oral. I'm normally more than happy to provide. Lube however tastes disgusting, so we don't typically use it. I have however heard some good things about preseed when TTC. I can get over the taste if it helps get pregnant, but does anyone know if this is safe to ingest?