I’m sure you are talking about the Zone 4 or 5 25-meter intervals. These are an exception, but as you pointed out, a challenge in a 50-meter pool.
The preferred method is to stop mid-lane, if it does not interfere with other swimmers or require you to rest on a lane line. The second best option is an easy swim for 25 meters as your recovery. Changing from a 25 to a 50-meter interval and reducing the intervals by half is also acceptable.