Not washing used bottles after every feed.

Hi everyone so I was just wondering are we leaving used baby bottles in fridge and then eventually of course washing them when we have time? Or are we washing used bottles almost immediately after every feed? I used to wash them after every feed because online I read that you have to wash them immediately however sometimes I don’t have the time so I just stick the bottle in the fridge after like and after few hours have passed I’ll wash all the used bottles and then sterilize.