So. Here I am typing with my left hand.

Front drain blocked. (Regular occurrence.)

Caustic soda applied. No success.

Boiled kettle.

To make sure boiling water got where most needed, deployed aluminium tube.

To protect hand when holding hot metal tube, wore glove.

Promptly poured boiling hot water on to gloved hand.

Glove soaked up boiling water. Hand scalded.

Trowbridge MIU dressed it nicely and did not point and laugh, and pain has abated considerably.

Drain still blocked.

Sigh.

Typing will be minimal till healed. Sorry.