If not for medical purposes: Even if you are using it via vaporizer ingesting, we still suggest letting it go during the cleanse. The reason why is not because it isn't "healthy" but that we are removing all stimulants so the body has a chance to return to its natural rhythm. Sometimes we have no idea how different stimulants impact our body until we remove them.
We suggest eliminating marijuana just while on the cleanse. If you are using medical marijuana for health issues (pain, seizures, etc) it's fine to continue.