That would be a great product to try. Rosacea is an inflammatory disorder most often treated with topical anti-inflammatory gels and creams. Because of their immune-inhibitory potential, THC, CBD and related cannabinoids are being considered for the treatment of inflammatory skin diseases. In fact, researchers, conducting a 2013 study on mice, concluded that topically applied THC reduced skin inflammation by decreasing pro-inflammatory mediators found in skin cells called keratinocytes. So, it would likely be important to make sure that the topical you try has both CBD and THC, such as the 3:1 topical you've chosen. You should also make sure that the topical product is unscented.
https://www.ncbi.nlm.nih.gov/m/pubmed/23889474/?i=2&from=marijuana%20skin Hope this helps!