My doctor's tip is to drop "eye drops" (Normal Saline) into the baby's nose. The fact is that saline can make the blood vessels inside the nose contract, so to stop secreting mucus.
It is very useful, since saline can be absorbed by our body without any harmful effect, you can use it as frequent as needed.
I found it very helpful and I think you can try. Since I have use this method, I do not need to use anything to suck the mucus out, which could be dangerours; I simply drop the eye drops and then wipe his nose.
Actually you can use those brand that can be found OTC, if you are worried, here is the brand my doctor prescript:
Martindale Pharmaceuticals
(contains: Sodium Chloride BP 0.9%w/v,
Benzalkonium chloride 0.01% w/v,
and water)
Hope this information is useful to you.