I don't think anyone has recommended plug cleaning for about 50 years. Seriously. This was common practice until about 1960 maybe. If they are working good leave them in. Otherwise replace them. PS, I had a Champion plug disintegrate on me and wreck my Supra engine. I take it back to the parts store and the guy says, "yeah, they do that." WTF??? I don't use that brand anymore. But hey go ahead and experiment, clean them if you want. I used to have great results cleaning dist cap electrodes. But they didn't have any platinum plating. I think the previous poster is correct, those look pretty far gone.

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra