I usually make the Sign of the Cross in front of them and ask them if they would like to have me answer any questions about the Catholic Church.
UU's? Probably 1/2 of UU's are ex-Catholics and know as much, or more, about the teaching of the Catholic Church as you do.
In my experience JW's don't give up that easily while the LDS missionaries are so polite that they respect your wishes.
Keep your day job.