Milk has proteins in it that are found in commercial conditioners and was used as a conditioner for hair before they became commercial. Some commercial conditioners actually promote that they have milk in them making them supposedly better.
Yes it will work and it will not cause bubbles:- because hair & fabric conditioners are both oil based and will kill foam. Don't use too much because fabric conditioners contain approx 2-4% actives (& over 90% water) and Hair conditioners are approx ...
Try going to a forum that covers air conditioners, not home theater if you want help.