Nostream comes up as a relay for me, if its a client I am struggeling to find it.
But yeah a throwaway profile is exactly what I have been doing, problem is that clients then still on their own like to fetch events directly from a profile with the inbox/outbox model. So I didn't have the kind of certainty I needed to know its actually coming from my relay for the more advanced stuff.
So far the nak suggestion worked best but its also tricky to use.