Half a cup???
I hate to break it to you, but that's a complete waste of 5 tablespoons of olive oil...'cuz at most only one tablespoon remains in the pump...the rest is flushed out immediately...the rest in a week or two. Once year may prevent the head from squeaking, but doesn't provide any lasting lubrication. Use olive oil if you want to, but to do any real good, you need a tablespoon every two weeks.However, eliminating the squeak is only part of the reason for keeping a toilet lubricated...the other reason is to prevent wear on the seals, o-rings, valves and the inside of the pump cylinder doubling or even tripling their life and the time between rebuilds. Olive oil, vegetable oil, Head Lube and other liquids that are just poured down a toilet are too thin to provide enough of a "cushion" between the seals, o-rings etc and the inside of the cylinder, or protect the cylinder wall from being scratched by salt, sand grit. Teflon grease, otoh, IS thick and very slow to dissolve...which is why toilet mfrs use it and so do the mfrs of swimming pool pumps...and why new toilets rarely ever need any lubrication at all for at least a year. But all I can do is advise...if you want to spend 2-3 x as much money on repair kits and replacement toilets as you need to, just avoi a 15 minute annual job, it's ok with me.