Oh, ya that's a possibility I suppose, but I wouldn't risk the other potential issues chemi-clean or its ingredients may cause in the tank imo.
I tend to think rtn/stn is directly related to a lack of biodiversity in tanks since everyone is using LR that barely resembles what real LR used to be and this lack of biodiversity that used to keep everything balanced and in check has now left systems on the verge of all these issues we see these days; like rtn/stn being one.