Brightening of sil-phos brazed copper

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We are oxyacetylene brazing C122 copper tubing using BCuP5 (15% silver/80% copper/5% phosphorous) brazing rod. Our standard copper brightening is based a mix of sulfuric acid and hydrogen peroxide ("pihrana bath"). This does a good job brightening the copper but leaves the braze alloy looking dark and smutty. Is there a different or additional chemistry that's copper compatible that will leave the braze alloy brighter and more attractive cosmetically?

Vern Rieck
manufacturer - Concord, NH, USA