My allergies were from outside influences (trees, flowers etc.), but I also got
it in certain buildings, like a store with carpets etc. Always sinus and ear trouble.
I have used chanca piedra the most, sometimes for 2 months in a row. The following at other times Gold Coin Grass, chinese bitters, phosfood, applecider vinegar.
So nothing constant for the 2 years. I took long breaks and I wanted to try different things because you don't know what the stone is made of.