Sanding a longboard?

[Qinetiqo]

Hi, the state of my longboard deck was getting quite bad so I decided to remove the grip tape by sanding down. However there's quite a bit of dirt which I can't seem to remove no matter how much I sand. I believe this is made out of bamboo from a carving system however I noticed there's a waxy layer which seems to be preventing me from getting rid of the impurities. I started of with 40 and made my way down to 100. It's very soft but obviously I won't re grip it until I'm happy with the deck. Thanks

 

[foxhole]

You probably have glue from the tape making things messy, clean off with lighter fuel first.

 

[Nozzle]

And if that fails use something a bit "lighter", like meths.