I am not sure milk and eggs would have any effect on heavy metal poisoning. "Heavy metals" is a phrase that generally applies to any metal toxicity, even though the heaviness of a metal is not what makes it toxic and many toxic metals are not heavy. Mercury, lead, and thallium are both heavy and toxic in certain forms, although their metallic forms are not particularly toxic. The fear and hysteria that accompanies metallic mercury spills seems excessive. There are well described methods of cleaning up spills that should not require evacuations of entire schools.
Because most of the toxic metals are divalent positive ions, it it common for intoxication to be treated with a divalent negative ion that is capable of bonding tightly to the metal. Search on dimercaprol or EDTA to learn more about real antidotes.
There are many practitioners who encourage people to think that their symptoms are due to heavy metal intoxication. At least in the United States, such intoxication is very rare. That doesn't keep unscientific practitioners from doing hair analyses and giving people incorrect diagnoses of "heavy metal intoxications". I would be suspicious of someone who claimed that he was treating heavy metal intoxication with eggs and milk. It could be a case ot treating a non-existent disease with an ineffective therapy. No disease means you do not need a good treatment. It's better than using real treatments that have significant risks. The main effect will be the transfer of fees from the patient to the "doctor".
I know of no other household remedies that are effective for heavy metal intoxication.