/diy/ - Do It Yourself

cheapest possible way to find my main line?
bought this house and the previous boomer that owned it was retarded enough to cover up the cleanout with rocks (arizona)
i tried calling him but his number is out of service and doesnt work anymore
the thing is, i know the fucker used to use the floor drain in the kitchen to drop oil and flush it out, but what i believe was years of doing this has cligged my sewage to a point where it takes 6 flushes to flush down a single pepple of shit and every 2 minutes into a shower it turns into a little lake
i just need to know where my.main is so i can at the very least install a new 2 way clean out