Valve Clearance on Larger Camshaft and Flat Top Pistons

I am gonna jump back in here:

famous bob said

taught to me by an 18 time national record holder : fill the valve relief full of clay , even w the top of the piston , roll the engine over in a complete /contiuous rotation , pull the head , take a razor blade ind slice the remaining clay in the pocket in half , "up and down" or vertically , it can be done perfectly if your careful , then measure with a depth gage of your choice , ACCURACY DEPENDS ON YOU ! ---------FAILPROOF!!

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"Measure with a depth gage of your choice". That's the issue IMO. Failproof? I don't think so. What is that magical gage that can measure a clay indent on a piston?

I tried that method a long time ago. I ended up with a bunch of pie slices I could not get a consistent reading on no matter how many times I tried. I thought those slices were important to me and so they stayed in my parts bin for many years. I recently threw them out.

I'll continue to use the dial indicator method and if I am close, I'll feel better knowing I may have 0.025 or so more clearance than I am measuring.