Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh

The rule about subliminal is the rule about any media. A media can be halal or haram depending on its purpose, function, and end-result. If these are beneficial and positive and contribute to the good in the world, then they are lawful. If on the contrary, they are harmful and destructive and promoting vices, then they are haram.

So ask yourself the question: What would be the ultimate effect of this work: good or bad. If it is undoubtedly useful, then you may pursue it without any doubt. If on the other hand, it would be evil, then shun it. If in doubt, you should avoid it to save your faith and honor.

The Prophet (peace be upon him) said, “Halal is clear, and Haram is clear; however, there are some dubious cases in between; therefore, whoever shuns would help safeguard his faith and honor.” (Muslim)

Almighty Allah knows best.