That's a high compliment and a challenge!
>> how to kill the slug eggs
Spray the soil surface with diluted ammonia. Hos deeply can the eggs be planted? You might have to drench the pot, but then worry more about roots.
I'm not positive what concentration dissolves slug eggs without harming roots at all, but here's what I read.
"Household ammonia ranges in concentration by weight from 5 to 10% ammonia."
5-10% divided by 5 = 1-2% by weight, effective on slugs & eggs
and
"Ammonia water: 1 part ammonia to 9 parts water. (Can spray the plant, but then rinse. If you've got Lilies or Asters be extra-vigilant.)"
Make up some ammonia diluted around 5:1 or 10:1 and put that in a spray bottle.
For proof-of-concept, find a slug and a mass of slug eggs under something like a rock, and spray them.
For proof of safety, drench ONE pot with that strength and make sure the plant doesn't suffer. Then drench ONE pot of a plant you think might be sensitive.
Flush after you think the slug eggs have died.
Meanwhile, put a little iron phosphate slug bait into pots with edibles, to deter slugs from coming back and laying more eggs. Just 2-3 pieces per large pot.
Maybe put a little metaldhyde slug bait in any pot with ornamentals, to kill any adult slugs that trespass.
