I have only seen Alumilastic used with icemaker
thermostats and never with a defrost thermostat.
If it is just a defrost thermostat then the clip is all
that's needed.

Same here.

Be sure to wrap them with electrical tape to
prevent water from getting inside the
connections

A little silicone or permagum works well also.

jeff.
Appliance Repair Aid
http://www.applianceaid.com/