In the past, I have lined molds with plastic wrap. Not that particular brand, and always got wrinkles on the bottoms and sides, but worst in the corners. It never melted when I used it for soapmaking. Clinging plastic wrap does not really cling very well to inner surfaces of containers; it tends to need to be pulled tightly to stimulate the cling and often may even need to adhere to itself to maintain a seal. But a seal isn't what you are after here.
I would suggest buying some and trying it and making up your own mind. If you use plastic wrap for other purposes as well, it would not go to waste. Walmart sells that brand, and I bought some and used it while I was in Texas last month, but only for food and for wrapping my Yellow Submarine soap. It tends to loose it's clingy-ness after being in close contact with MP soap, BTW.
I would suggest buying some and trying it and making up your own mind. If you use plastic wrap for other purposes as well, it would not go to waste. Walmart sells that brand, and I bought some and used it while I was in Texas last month, but only for food and for wrapping my Yellow Submarine soap. It tends to loose it's clingy-ness after being in close contact with MP soap, BTW.