[Christ]

From experience, you want to go through a couple warm up cycles (20+ miles) if you expect the sea foam to do anything.

An alternative to this is to use a solvent, thoroughly drain the oil from the crankcase, install the solvent, and manually work the oil pump for 10 seconds, repeating 10 second bursts every 5 minutes or so.

If you drain the solvent and it comes out cleanish, put in some cheap oil, then flush the block with itto remove any leftover solvent. Add your new oil and filter, and your good to go.