When Hugh was little we used the nose sucker outer thing with the saline drops but I don't think he would have tolerated that when he was 7 months old? Might be worth a try. I think it was the FESS one you get from chemists.
Some people I know have a big long snot sucker-out thing but we never did.
We just used to keep wiping and tried to use aloe-vera soft tissues
He's only just learnt to blow his nose now at 2 years.