depends. do you use porous bowls like plastic or wood? (and if so, why???
) if you're using non-porous bowls and tools, then cleaning them and maybe soaking them in some vinegar or lemon juice solution should be sufficent to remove any traces of grease or odours. if you're using stainless steel or glass and your bowls are very scratched-up, just be sure to scrub the scratches well.
a "gumpaste bowl" won't affect your cake batter, but a "cake batter or icing bowl" may affect the gumpaste if there are traces of fats/grease.