There are two options, the one already mentioned, and wrapping an extra long "butyl cone" around the screw. The biggest problem with screws and wood is in properly compressing the Bed-It Tape, between the fasteners, without bowing the wood between screws or stripping the screws out of the deck. Balsa or foam are not known for their ability to hold a screw..I figured that's what you meant.Thanks!
The optimal course of action would be to replace the wood screws with machine screws, if you have interior access to the underside of the wood. You can also stand on the wood to allow it to displace the excess Bed-It Tape to prevent further creep/bleed..
Bed-It Tape is specifically formulated to have minimal creep or what is called "cold flow", but this requires the fitting to be properly torqued in order to displace the "excess" product from under the fitting. Screws do not always have the strength to do this and wood can bend/deflect and not fully displace the product.
That said I have bedded plenty of mahogany & teak with Bed-It Tape, it just requires the proper technique to achieve the desired result..