How to properly clean a bundt mold without ruining the surface

I usually do the suggestions in my previous question for seasoning the Teflon coated (non stick) bundt pan (buttering and flouring) and I have no problem with that. The problem is with leftover residue,I cannot clean the pan properly. After a few times of cleaning, the surface is hurt and since it is an fairly expensive, I am a little worried. I gave it a long soak in hot water and it didn't work. I also found this question which seems to ask the same thing but the answers are not about cleaning but the other part of the question.