I can see why the yellow arm bands so prolific in the 60s & 70s have been phased out, if an actual German can't remember the difference between the blind symbol and the deaf symbol. The memory-aid I used as a kid was to note that "two dots up" looked similar to a face, which means blind. The symbol with the two dots at the bottom means deaf. The three white dots on a black oblique bottle mean you have some really upset people in your facebook feeds, apparently. If you're going to read into things, at least do it right.

Also, I think the word you're looking for regarding the hashtag #schluckimdunkeln is "innuendo", not "pornographic phrase". With the right intonation I can make a cake recipe sound dirty. Oreo's "You can still dunk in the dark" sounds naughty too, as does their Swedish tagline "vrid, slicka, doppa" (twist, lick, dip). Point being, copywankers are everywhere, and some people find it funny.

p.s. to add to the confusion in Sweden we had five dots like this to mean blind. Five dots = b l i n d, three = d ö v (deaf).