My justy rear shocks/struts were pretty bad ...no one seems to be able to get..

I drilled a 1/8" hole near the top of the shock(used vacum attachment to prevent any shaving from getting in shocks) went to cycle shop and got 20w fork shock oil,... put some in shock and it now functions like a shock again....been on the car 7 months and still working...

sealed hole with nitrile washer and screw...

Not a bad idea at all. How did U get enough threds in the shock body to keep the screw tight? Did U tap them, or are they sheetmetal screws?

I'd guess a sheetmetal/self tapper was used. The washer is actually doing the sealing, but if hole was not too large, the screw itself will seal like a charm. Better yet, the screww is doing the sealing and the washer is there just for good measures.