I would not worry about your shampoo etc and just pack it. If they take it - of well! But do try and not check your bag in as the waiting to collect it will eat into your time. Immigration entering the Philippines is usually not that bad. If you can avoid the baggage handling then half of your battle is done.

I have never seen a transfer desk at Manila airport. I guess you do have to enter the country and recheck in again. If so, remember the airport departure tax.

Sounds like a pain to me. Are you sure there is no transfer desk for ongoing international flights?