I did free chair massage at a Curves a couple of times, but only got one client out of it who only came a few times. This was very early on in my career and I have since learned that it is CRUCIAL to keep in contact with these people and you will eventually pick up a few of them. Just going in twice was not really enough. They need to see you there more often and kind of get to know you before they will book a full session.
I also did a few things at Ladies Workout Express. At once I gave a little talk on stress or something and also did free chair massage. I did not give out any discount coupons, which was probably an error. At another one I did chair massage and it was getting close to Christmas. I sold quite a few gift certificates and also booked a few clients.
At another Curves I just asked if I could display my brochure and cards and they agreed. One of the workers there became a client, who recommended her family and cousins and they recommended people and it has really turned into a TON of clients for me.
They are all individually owned and I think it would probably depend on the owner whether they are going to "bend" any rules that the company has about promoting other services. If you are approaching the Curves that you used to be a member of, they might be open to the idea. I say to give it a try. All they can do is say no.
If you do chair massage there, I would see if you can do it a few times so that the members get familiar with you. They maybe can chat with you or they will see you in action and begin to build trust. Giving the owner a free massage might help her to promote you. One of the owners of the LWE was very enthusiastic about me and I think that's what helped me out there. I would definitely recommend a coupon of some sort that has an expiration that is fairly soon. Maybe give them some sort of extra bonus if they book their appointment right there on the spot. And most of all, get their e-mail addresses and send them e-mail at least once a month about specials or just tidbits of information you have found. Be funny, upbeat, informational and don't just be asking for appointments.