Ailz bought these gutter-cleaning doodads on line. They take the form of fat, little bags- bigger than tea-bags, but small enough to fit into a clenched fist. You throw them up on your roof and they dissolve in the rain and release lots of micro-organisms which eat the gunk that's blocking the gutter. The angle was too steep for me to throw them with any certainty from our cramped backyard, so we asked Shiraz next door if he'd do it from his- which he did. And now- right on cue- it's raining.