In BW1, it is near impossible to cover every single pokemon with a hard counter. So I decided to cover chansey through playing rather than a single pokemon. Toxic Spikes on Forretress really wear down Chansey very fast, but it faces one main problem against rain stall (where chansey is most likely found), Tentacruel. Thus I chose my Heatran set which can lure and heavily damage Tentacruel to the point it will either die to hazards next switch, or will just die to Heatran. Then I can lay Tspikes and kill chansey that way. Of course I will test your idea of Refresh, but I will be vary wary of losing Substitute on Latias, as it loses a lot of its potential vs faster teams then. I just wanted to say that on paper Chansey looks very tough, but in the game it is easier to negotiate around. Nevertheless, thanks for your comments and I will think about refresh and see if it is worth the loss of substitute.