For frozen or rusted parts, what I have found what works best is to use heat and not cold. Find a pan that is large enough to hold your rusted together items, remove any wood, put in the pan and cover with Kroil. Bring the temp up to 300 degrees and let it "cook" for about 3 hours. Remember to keep an eye on the heat because all petrolium products have a flash point. This will allow the pores of the metal to open up and also thins down the oil so that it penetrates better. It will soften the rust. You might have to do this several times depending on just how extensive the problem is.
No such thing as a stupid question. What is stupid is not asking it.