Glue sticks for print bed
As mentioned by Matt - PVA glues work perfect for both filaments.
It works well because it's softening temperature is between 45..85C so it's more or less temperature of HB.

Advantages:


cheap
easy to apply on HB
can be applied on cold as same as on hot HB
sticks model very well
non toxic, no solvent, odorless
easy to wash (from HB) (just wash it under water or scrape with sharp tool)
works very well even with old and dry layer of glue


Disadvantages:


quite hard to detach model (I use paper knife)
first layer is not glass-perfect
after detaching, model is a bit sticky (first layer)


I use Scotch Glue Stick by 3M.