So after smoking my pipes i make it a point to clean the rim of my bowls with a q-tip and saliva as to not accumulate excess tar (not so attractive) but I have an Ashton bent billard xxx with pebble grain that holds some tar in the crevices and when i clean it i notice a little bit of the color come out....my intution says not to clean it but how with the tar buildup affect it over the years and is that the right thing to do?