There are some of these things that will melt if oil is at operating temperature. I don't know which ones they are, but I would recommend that you find one that will work okay at operating temperature. Removing the oil when engine is hot does a much better job of cleaning the inside of the engine. The contaminants are churned up in the oil when it is hot, thus will come out rather than remain adhered to everything inside the engine.
Secondly, if you elect to change oil this way, I would strongly recommend that you raise the car and look around underneath at least as often as you change oil. This gives you an opportunity to check for leaks and to see if anything is "falling off." This is one of the many reasons that I still rely on a good old fashioned drain, because I have to raise the car and inspect anyway, so I might as well drain it and save the trouble and expense of the gadget.
Change oil hot and change oil often,