and it's not BS at all, you can clean the filter with lukewarm water, however it needs the regenerating grease to cover the filter compound once again after it's fully dried, I know it's a spray grease designed to trap the harmful dust particles from passing through the filter paper compound and of course I don't know the formula but in the absence of the real thing, I suppose try some other light spray grease stuff like wd40 or other. Don't quote me on this I am just assuming.