Cleaning oil pan sludge without dropping it- before changing to detergent based oil

[Timsalways]

Originally Posted by Timsalways

As a rule of thumb, how often should the pan be dropped? I have a 1930 Tudor and dropped the pan to fix an oil leak and found the main tube was missing, the oil leak is fixed, but I read somewhere it should be dropped every so often because there is no filter

I like all Yall's answer! Looks like I'm good till the oil leak gets worse I started using a 15/40 diesel oil in it lately, she was on 5/30 for awhile, till I found out better. Thank you all for the help