I havent ever used any type of power steering leak sealant, it seems that for the price of a rebuild seal kit it isnt worth risking ruining a pump because it leaked down again..... Of course that just my opinion, but if you do want to rebuild your power steering pump or power steering rack (which ever one is leaking) I found this site and they have LOADS of seal kits, and they seem to be very well priced.
www.pskits.com