Loctite 242 can be found in nearly all orthotic and prosthetic facilities. I have always wondered if there are alternatives but have not bothered to look. I typically carry Loctite 248 in a glue stick form however I will be trying a new brand shortly. Here is the stick version of Loctite which is nice because there is no mess.
Frank Hodges from Sunstone Lab showed me what he is using as an alternative. Vibra-TITE in Gel Form in a Pump, no mess and way less expensive, plus they have a funny brand name of another type of glue on their website.