Sanding Slits

[masonsailor2]

Gene do you have a plunge router ? That will give you the best results.
Paul

[Beave2012]

Could always remove the majority with your original method then chisel the edges. For sanding a small Drexel sized drum sanding bit would make it easy.

Overall I do agree that a router, plunge, fixed, or router table would be the simplest and most effective way.

[Gene Howe]

I have several routers. The little Bosch in it's plunge base would do the trick.