I like Astroglide as well. I'm 10 yrs PO and still use it. I used a generic KY for about 1 yr following surgery. It worked well, but dried too quickly. One thing I noticed about Astroglide though is that if you don't douche soon after you use it then you quickly get that "not so fresh" feeling (smell) down there.
As for the white stuff, at six weeks that's likely to be sloughed-off skin as you mentioned, but it could also be a yeast infection. If you haven't already, I highly recommend that you find a nice OBGYN and have her take a look and perhaps run a test on the stuff. It's definitely worth it. There are some very friendly OGBYN's and it's not hard to find one that is either open-minded or has had previous experience with post-op ladies.