I always decap (punch out the primer) after I have washed/cleaned the brass because I did not want to get dirt in my dies.
I use a Decapping Die from Lee before cleaning. This die does not touch the brass at all. Only the decapping pin touches the old primer.
Then, I clean the cases.
The exception is range brass or military once fireds. These go through a bucket of hot water with dishwashing detergent, and then rinsing before I touch them.