For the knives and handles:
1. Especially for untreated handles, oil them frequently. Oil will prevent absorption of other stuff.
2. Wet them with clean water before you start. Any dry parts will saturate with water and that will prevent other things from soaking in.
3. Wash them very thoroughly after with soap and water.
4. If there is still smell, use alcohol, lemon juice, hydrogen peroxide, very diluted bleach. I would try them in that order, more or less. Just remember to neutralize if needed, and wash thoroughly after. Re-oil frequently, especially on untreated handles, as any of these treatments can dry the wood badly.
I cut sashimi on a wood board (Boos maple) with an untreated ho handled yanagi, and neither absorb smells at all following steps 1-3. I've felt obliged once only to go to step four on either: that was before I realized that step 2 was critical; I used very diluted bleach to annihilate the smell.