Oral chelation is, well, when you take chelating and sequestering compounds via mouth. Chelation has typically been administered via IV or Rectal suppository route.
IV Chelation typically seems to employ the use of EDTA (calcium disdium EDTA) along with other vitamins and minerals in an IV drip. ACAM stuff.
Rectal Suppository chelation was started by a company called Nanobac who patented a process using calcium disodium EDTA suppositories. That product is called Cal-Detox (www.cal-detox).
Both the IV and Rectal routes are prescription only...BEWARE of any rectal EDTA product that is OTC...thats trouble!!!!!
Oral chelation product are relatively new. Basically, you get EDTA via oral route. Problem has been, EDTA get TRASHED by HCl in the stomach, so most oral chelation products arent effective. Thats why I like the calci-clear product...it uses an enteric system to get the edta past the stomach and, more importantly, it uses a combination of cleansing and chelating agents to compliment the EDTA...so you get a broader range of cleansing (imho)...works for me.