This may be a duplicate based on "Do you know when you are under the effects of a charm/domination spell?".
In a recent session our group were fighting Mind Flayers and were repeatedly subject to domination spells. As a Paladin I opted to use Cleansing Touch to end the effect of the spell on myself.
Cleansing Touch from the PHB:
You can use your action to end one spell on yourself or on one willing creature that you touch.
Our DM allowed it, based on the fact that the description for Dominate Monster doesn't explicitly state that I couldn't end the effect in such a way, but RAW should I have been able to?
Dominate Monster from the PHB:
You can use this telepathic link to issue commands to the creature while you are conscious (no action required), which it does its best to obey. You can specify a simple and general course of action, such as “Attack that creature,” “Run over there,” or “Fetch that object.” If the creature completes the order and doesn’t receive further direction from you, it defends and preserves itself to the best of its ability.
For clarification, I failed the Saving Throw and the Mind Flayer issued a general command of "Kill this PC", never assuming direct control of my character.