Yes, you can do a Liver Flush without Epsom Salt and, indeed, Doc Sutter even recommends not using Epsom Salt for liver flushing.

I concur with his outlook that the claimed effectiveness of Epsom Salt for supposedly 'dilating' the biliary ducts may also be precisely the reason why it may be an unwise thing to use. If larger stones make it down the common bile duct then they otherwise would have done (in the absence of large quantities of magnesium sulphate), then there is a possibility that such large stones may not succeed in passing fully through the bile ducts and may become lodged (choledocholithiasis), which is seriously bad news, generally requiring urgent medical attention.

Furthermore, consuming huge amounts of magnesium sulphate is an unwise thing for someone with calcium deficiency to do, since calcium and magnesium exist within the body in specific ratios to each other. If one is calcium deficient then how is the body to balance a huge intake of magnesium? Doc Sutter and I have discussed this in the past, since we each share personal experience of exactly this scenario.

Many people do fine flushing their livers with the inclusion of Epsom Salt, but some have problems and many do fine without using Epsom Salt/Magnesium Sulphate.

It might have been Andreas Moritz who popularised the inclusion of Epsom Salts in Liver Flushing but I'm not certain about that.

Short answer: yes, you can flush without ES if you wish to.

Either way, there is always some risk with any procedure, of course, so you have your own free will in choosing what you do with your own body.