How many times can I feed suicune?

So I’ve used my suicune incense and the suicune would need one bonus and three superball biscuits to be caught. Now, I’ve experienced it a couple of times that Pokémon would be full after three cookies and I don’t want to waste this chance to catch it.

Would I be able to use these biscuits instead of a masterball biscuit or would it definitely be full after the third one?