Are you all so sure that that is what blocks them?
Where I work it is standard procedure to pour the remaining very hot coffee and the remaining boiling water used to make tea down the very small drains at the end of the shift.
If we don't then very soon the small drains get clogged with a grey slime which resembles a fungus/bacteria hybrid.
Hot chocholate residue is another main cause of blockage. The drain slime feeds on it.
Someone in authority should have these "blockages" analysed.
(P.S. the drains from the ice bins produce a really nasty slime of a different colour, who would have thought some exotic beast could live in a drain fed only by ice melt?)