Hi there, wizzel!
I currently use eggs (yolk only) to wash my hair, in combination with soapnut liquid and lemon juice, but before I had soapnuts, I used just 1 egg yolk, 1/4 cup beer (or lemon juice) per wash. You can also add some herbal tea if you want. Peppermint and/or rosemary is very nice, and it helps with the egg smell. I find that if I don't rinse thoroughly enough, the smell is a bit unpleasant, but honestly, unless someone buries their nose in your hair and takes a good sniff, they won't be able to smell it. However, if it does smell bad, you can take 1 drop of any EO (essential oil) and distribute it evenly through your hair. Or if you oil your hair after washing it, then you can add EO to your normal hair oil and apply it as you usually would. Either way, it'll take care of the smell.
Hope this helps!