The reactions I have experienced rang hugely. At one end of the spectrum it is not uncommon for me to get no reply at all to a polite enquiry. Others have stated they aren't interested. Then at the other end of the scale I have had girls get wildly excited about it thinking it looks hilarious, lots of fun etc and desperate to do it. Other girls have sought me out, one recently made a 500+ mile round trip just to do the shoot! Between the two you have others who are just professional about it ask plenty of questions but just treat it like they would any other job. A common question is where I got the idea from and what the gunge is made out of and is it safe etc.
Seconds everything BosunBob said. One of my models once drove from Ireland via Scotland, at her own expense, in order to do a shoot, because she thought it looked like so much fun - she loved it and has come back for several more.
I've never had a bad reaction, though have had a few polite declines.