If u want u can use as a flush yung mura na oil lang. Yung pinaka mura.

After you drain it just put the cheapest oil then paandarin mo lang nang 2 to 3 mins. then drain it again u will see na medyo dumumi yung kalalagay mo lang na cheapest oil.

Then put na yung ano mang gusto mong oil, kung synthetic or semi synthetic.

my 2 cent lang...