Then I quickly switched the topic to about them - so where are you from? How do you like this city? Etc. It always resulted in a very relaxed and pleasant commute, chit chatting and telling them about local attractions, answering questions they had about getting around etc.
This is my strategy as well. It's always pleasant. Helps to know a bit about how the missionary process works, but they'll tell you if you ask.
My back yard fence is the border between my house and a missionary house. (Usually 4 are staying there) They shift every 6 weeks, so depending on a lot of conditions like weather, season, etc. sometimes I get to chat, sometimes not. But it's always amiable, Generally I let them know we're Hindu fairly soon in the conversation.
A couple of weeks back we had 4 over for dinner. I chanted our Sanskrit food blessing, and one of them said a prayer. Vegetarian chile this time. It's a bit of a treat for them, not having to cook for themselves, company. I asked about how often they get invited over, and it's rare, although one guy said he spent 6 weeks (they move and switch companions every 6 weeks) where a Muslim family fed them often, but generally it's church members. One chap was from New Zealand (I'm in Canada) so he was a very long way from home. The other 3 were from the US.
Mostly we just talk about their plans after the 2 year stint. One guy was quite funny, as he said honestly, "I have absolutely no idea." Typical adolescent, that way.
After dinner one asked to share a short scripture. It was on developing humility. Then I took them into our family shrine room, introduced them to our Gods, showed them scripture, picture ofs the Gurus, etc. So it's a mutual sharing of information, and not much else.
Over the years we've met quite a few. I admire the discipline. Things like punctuality, fulfilling commitments, purity of mind, sticking to a very limited budget, are all admirable, and are excellent training for adulthood. So they will become good responsible people on this planet, enriching the diversity of religious thought.
As far as proselytising goes, I have a sign on the door. It works. Nothing more has to be said.