There is no such thing as “clearing out a subliminal”.
The subliminal has either installed a new belief into your mind or it has not.
Most of these amateur YouTube subliminals are scripted by unprofressionals, often even teenagers, and their subliminals in 99.999% of the case are not installing anything into your mind at all. The subconscious mind might act upon certain suggestions short-term for a few days and then will usually return to its “normal” baseline of deeply seated core beliefs.
But there are people here on the forum, who believe it is fine to listen to unknown subliminals from unkown people…well lol, it is their subconscious mind and they can do whatever they want with it.
In my personal opinion, people who are not guarding their subconscious mind like a holy temple, don’t know what they are doing in the first place.
The only way to “remove” a subliminally programmed belief again is the same as one would remove any other belief:
To become aware what of that belief and/or then use guided smart fields or techniques from Energy Psychology like EFT/BSFF etc. to remove those.
Or to use fields that would overwrite the old belief with new beliefs.
Fields like Subconscious Limits Remover, Smart Tap Tapper, the various trauma healing fields etc. can help as well.