In addition to bad stuff, enemas do remove good bacteria from the intestines which is why I do a probiotic enema after all the others and use oral probiotics as well.
My feeling has clearly improved after doing the enemas for a couple of months.
Silver fillings are only one source of metals. There are many others too. Heavy metal problems are probably very widespread, especially in countries where the water isn't safe to drink but is still used for cooking.
Spirulina is not enough for chelating. It's only effective for removing metals from the digestive tract. You need another chelator to remove the metals from the places in your body where they get stuck. DMSA, ALA, DMPS are three examples, but there are others. It would take careful and systematic use of a chelator to remove metals effectively and safely.