Q: Super Seal for A/C with no leaks?

I bought my car about 9 months ago. Considering it was October when I got it, I didn't really use the A/C much and never gave it much thought. A few times I accidentally clicked the button and noticed that I would hear a weird whirring noise accompanied by a small jerk from my car, however, once I turned the button off, this stopped. I told the Ford dealer about this and the mechanic there explained that my A/C had probably just run out of coolant and was cycling. He said to fix it would be about $100 in labor plus the cost of coolant. I put it off for months since it was winter, but now that the weather is warming up, I'd like to try to fix it. I went ahead and bought one 12 oz. can of R-134a and a "Super Seal" kit made for R-134a A/Cs by the brand A/C Pro. I'm not 100% sure that there's actually a leak, but would it be safe to go ahead and run the Super Seal through before the coolant just in case, rather than buy dye to run through? Will this harm my A/C if there's no leak? Thanks

My car has 81000 miles.
My car has an automatic transmission.