Just have a question about regular chain maintenance, and wondering if I am doing it right, or too much - any input would be appreciated.

I commute to work 20 miles one way daily, so I ride around 200 miles per weak on the city streets. It's not as tough as it sounds, since I use electrical assist bike, but it's still pretty hard wear on the drivetrain.

I clean the chain once a week with Finish Line grunge brush and bike chain degreaser, and after drying chain clean with towels I apply 3-in-one oil to each pin in the chain, removing excess oil with clean towels. 3-in-one oil is [much] cheaper than purpose bike oil, and it does have bicycle icon and "long lasting" verbiage on the can - which makes me believe it's an okay oil to use.

The chain is super smooth and makes no noise whatsoever first couple of days after that, and by the end of the week I can hear something that resembles normal drivetrain noises, but I never heard squeaking in between chain cleaning.

Is this all normal, or I am doing it way too often? Does using non-purpose oil making it all worse, would it be cheaper to use some sort of professional oil but less often?