What do you expect to get out of this?
Limbaugh will be a first offense user. He will probably nolo and get a suspended sentence at worst. This will have zero effect on his popularity with the dittoheads. If he stays clean, anyone that brings it up a year from now will be ridiculed.
The only thing you can hope for is that he fails to kick it and spirals down like many drug users. Otherwise, he will be back at the same old stand, raising your blood pressure.
If I were you, I would do my best to avoid the subject of hypocrisy. It is ubiquitous in politics and public life in general. To deny that is the ultimate hypocrisy.