Flushes are not that effective in terms of clearing the liver, the gallbladder yes but the liver no. There are a number of things such as increasing methylation, use of herbal Liver Cleanses and phosphatidylcholine which will deep clean the liver. And while doing this make sure you use vacuums to sweep the colon while the liver is dumping otherwise the toxins just recirculate. Bulk charcoal is a miracle and users report that clays (pascalite or bentonite) work well.
Vegans typically have B12 deficiencies and with that problem then methylation becomes impaired as does the all important protein metabolism and without protein metabolism then everything else becomes defunct.