While fitting metal to wood there is fine metal impregnated into the wood of the stock. I've read not to use steel wool because the pieces left in the wood will cause reaction and spots in aqua fortis finish and assume this will cause the same issue. How do you remove the metal from the wood. I've washed it to whisker and sanded and got most of it but some seems to be pretty deep. Any suggestions and how do you prevent this when fitting parts?