The beatings delivered to a person who has just farted. The only way to stop the slogs (short of waiting for your beaters to become bored) is to recite the alphabet, forwards then backwards, then naming three teachers. Shouting "no slogs" immediately after farting offered some defence, but not if you were unpopular.

In our area (South London) you had to name three pubs and whistle in order to stop the beatings.
PS Beware saying 'No Slogs' in case the other person says it at the same time and 'jinxes' you.

In our part of South London (obviously a different part from Mr Alexander), as soon as the noxious whiff of a fart was detected, the detector would start to count in a low voice, and the number that was reached before the guilty party was either identified, or identified him/herself by saying "no slogs stop" would be the number of beatings, or "slogs" received from the counter. An obvious tactic, other than simply saying "no slogs stop" as soon as he/she farted, was for the farter to start the counting themselves, hence avoiding suspicion, although most people saw through this elaborate ruse. Certainly in my case they did, anyway.