This is what my neighbour did, for years. He would take the eggs & poke a hole in the bottom & top & would blow all the stuff out & return the eggs back to mom. Mom would nest & nest & nest until she the eggs took too long & then would reject them..

He siad he tried just tossing them out & it did no ggod, she would just lay more to replace them.

I think he had the birds for 10 years & did this all the time. Hes birds were very nice & chirped all day long outside with him while he gardened.