The options we are interested in are OPERATION_CLEANUP_ENABLED and RETENTION_WINDOW. By default, RETENTION_WINDOW is 365. and OPERATION_CLEANUP_ENABLED is TRUE.
Since we want to set our retention window to 10 days, we need to update RETENTION_WINDOW to 10. We could do this with a simple update statement, but Microsoft provides us with a stored procedure that will do that for us. The benefit of the stored procedure over the UPDATE statement is that a vendor-provided stored procedure will typically encapsulate any additional steps required.
I do not at all like the idea of running SHRINKDATABASE and definitely wouldn’t have that plus a backup in the deletion loop, but if you get caught in a nasty situation with SSISDB, this can serve as the starting point for digging yourself out.