After extensive whacking when the instrument failed to suck properly, I discovered this secret place, and promptly pulled out enough fluff to leave
Much muffled cussing, a wrongly shaped piece of purple plastic, some tweezers, and finally an old toothbrush later, I think I managed to clear out the problematical passage.
The floor is actually becoming clean, much to my amazement and delight. Now, we'll see what happens when I try to move the bed...