What is this white crust on my MMS bottle?

I've been taking Miracle-Mineral-Supplement for nearly 6 months now. I'm very pleased with it becauses I never caught any colds/flu during the holiday season, and I've not missed a days work since I started taking it...

After more than 6 months of using it, however there's a white solid crust that's developed on the spout of the bottle...anyone know what this is?

BTW, I'm down to doing 6 drops a day. The most I did was 12 drops. I continue to work myself down one drop per week until I hit 2 drops per day. Any thoughts on this from those of you who are more proficient than I on this topic?

Thank you! Tweet