Variable Check module fixes error

One of the websites I manage started to get the following notice even though I have the logging errors off:

Notice: unserialize() [function.unserialize]: Error at offset X of X bytes in variable_initialize() (line 749 of /<sitepath>/includes/

After checking out the line in bootstrap, I realized I had some bad variable in the variable table. But I have over 800 variables in that table. How am I going to find the culprit?

Variable check module to the resue -

This module lists all entries in the variable table that cause these unwanted PHP notices on production sites.

After enabling the module, I visited the status page that provided a link to fix the error(s) found.