The only caution I can think of is that wood tends to absorb resins and so also flavor. If it was me I'd want to dedicate a piece to only changa or only MJ. Don't think I'd want my MJ bowl permanently holding the flavor of DMT in it.
SWIM actually cleans out the glass bong bowl with alcohol between uses, and will probably get an entirely separate setup for each at some time.
Images of broken light,
Which dance before me like a million eyes,
They call me on and on...