Yep, I have for years. There are mainly two different types. One reads the temp off your pyrometer and the other is a timer based device. I wanted the Isspro TT but they have interface issues with some 2000-2001 vehicles where the Key Fob doesn't work. There is no way to tell which ones will be affected!! Not a chance I wanted to take. I ended up doing my research and decided on a Brite Box Turbo Lifesaver. I feel this is the very best TT on the market!! I can set the timer for extended run times out to 150 min. Since I take my Bassett Hound with me wherever I go this feature comes in handy in the summer when I have to run into the store. I can leave her in the truck with the AC on!! It also has a micro kill switch that I use when I go down to the city, very nice to have!! It also has a feature to prevent dry starts after a oil change. Sure I could of bought an alarm with a TT for what I spent on the BB unit alone, but I have a few friends who have the TT in a alarm and they don't work right at all!! I have never had a problem with my BB unit. The majority of time 1 min is enough time to drop the temps to 325 or lower.
Some say coking isn't a real problem anymore, but under the right conditions it is, and I have seen the sand like material that comes from it.
NCH