In that case whats the best way to clean them? Compressed air as some have suggested or maybe try and fashion a snake of some kind?

I had the same problem on my 2000 ssei with water leaking in the same way ..In the front drain holes when I poured a bottle of water it was draining very slowly...So what I did was, I had a old fire extinguisher the type that you fill with water and pump air into it..I added water to the fire extinguisher and pumped it with the air compressor from the trunk..I put the nozzle of the fire extinguisher in the drain hole and let it rip..I could see the water rushing out of the bottom..when I took the nozzle off the drain hole the water drained so fast I can hear the suction sound...Maybe this will help you.
Rod.

Yeah, I might try something like that. ...I don't suppose Drain-O is a good idea. It rained most of the afternoon today and I haven't noticed any additional water intrustion, but I am gonna try and make the drainage as efficient as possible. Thanks everyone I really appreicate the help.