The Peter White triple-izer is a bolt on which works well. Key, as Sixty-Fiver pointed out, is the BB spindle length.

I sent a Campy drive crank arm to Elliot Bay Cycles in Seattle, to have Bob Freeman drill a permanent triple-ized bolt holes. I turned a Super Record into a Campy triple that could take smaller inner rings than the original Campy triple (that, at 100bcd, was limited to 36t). It was slightly less expensive than the Peter White solution, but only just.

This is my crank, post drilling:

I did swap out the bottom bracket to a proper triple BB, tho.

It's worth it to get those lower gears. IMHO, of course.