If I recall correctly, the primary method of "punting" was to send an instant message with a bunch of unclosed HTML tags, which the client's renderer wouldn't be able to handle and would crash the AOL application.
The unclosed tags were one method, and the other was applying a different formatting to every character. Even one or two messages of maximum length was enough to crash the client.
An IM with repeating <h1><br> tags until you hit the character limit was good for about 30 seconds of lag/freezing on the Mac client. 10 of those in fast succession would pretty much make you have to restart your computer.