Ive read somewhere to rub some wax from a candle over the hole to repel/seal any water from that area. This was from our tent camping days but would assume it would work on a HTT also. Havent used the tent since out TT purchase but held up for a few years, no leaks if I recall.
*Currently trailer-less but shopping
07' GMC Envoy w/ P2 controller (current TV)
88' Chevy K5 Blazer (soon-to-be TV)
74' VW Superbeetle (1303)