add script execution to lock screen

[mrford121]

Hello all,
I hope I am posting in the correct section as this is my first time posting on here. I am currently running BT5 R3 as my daily os and have had nothing but great experiences so far. However, I am getting a little tired of constantly clearing my ~/.thumbnails manually all the time. I have placed a script to be executed on system shutdown but quite often my machine stays on for days (sometimes weeks) at a time. My question is where I should look to add a script to clear this folder whenever my computer initiates the screen lock?

[sickness]

A good alternative to this would be to setup a cron job to run the script at a regular time interval.