Unless you are using silicone brake fluid, you do NOT want ANY silicone mixed with it.
No brake fluid wants ANY petroleum grease mixed with it.
If your seal has expanded, it has absorbed what ever you treated it with, and should be discarded.
There is pure silicone grease, and there is grease with silicone in it. They are not the same thing. Reading labels can alert you to the difference.
Brake seals are installed with brake parts assembly lube (preferred, but hard to get these days in some areas), or whatever brake fluid you are going to use in the hydraulic system.
If you rinse your swelled seal in brake parts cleaner solvent, and then let it air dry for a few hot days, it might shrink back to proper size. (But, I wouldn't use it, unless a dire emergency occurred.)
Cheers,