Has anybody tried applying durable water repellent to their street clothes?

I tried an experiment on Sunday, spraying a pair of cargo pants down with Granger's, drying them to "activate" it, and then biking about 25 miles. The result: it didn't rain. This stuff is great! They've been predicting nothing but rain for the next week in the Pacific Northwet, and the clouds were so frightened, they didn't release any water... Or maybe the forecast was wrong. It rained a bit yesterday, but as timing would have it, I was indoors the whole time.

I had some intimate contact with the lake, and managed to stay dry, but that's a long story. When I got home, I wet my hands and "shook" the drops at the pants, to act more like rain; as expected, the water beaded up like mercury, and rolled off.

But I've only tried that one pair of pants, and can't wear them every day. So I haven't been able to really test this idea. Has anybody else tried DWR'ing the stuff they ride in?