A crowd control substance ideally is repellent in several ways, as well as difficult to remove.
To this end, consider “Bee Go”, a UV colorant for covert ID or use a vibrant color for visual ID… maybe add some glitter for festiveness. Area denial/mobility barrier is from large amounts of veterinary “j lube”. Anything with a mercaptan, and don’t forget hunting scents like fox urine analog.
I suspect that the manure cannon may be a tad difficult to get close enough to the festivities.
The best methods leave the commies perplexed, smelly and unlovable. It disrupts their propaganda and puts them on the back foot. Even just sliming an area (to borrow a chem warfare term) that they want to move through will disrupt them.