There are many ways to cleanse yourself of negative energy and/or emotions which have accumulated after helping others. There are meditations, stones, smudgings, salt baths......and many more.
This particular technique can be done anywhere and at any time. It takes only a minute to do. But at best, it is only a quick fix for momentary relief.
An example would be taking on the negative emotions of a friend at work who was reprimanded. Since you are at work and can not leave immediately to go and cleanse yourself, this would be a viable alternative until you were able to get someplace to cleanse yourself.
Close your eyes. Picture your chakras full of swirling energy. Imagine the heart chakra in your minds eye. The heart chakra is the base of emotion. Now imagine a flower (I prefer to picture a lotus blossom) blooming out of the core that is your heart chakra. See the flower in detail. See the center of the flower and imagine pushing out all of that negative energy. Picture black gas( no fart jokes please) being pushed out of the flower's center and dissipating into nothingness in he air.
The reason this works is because chakras are energy portals. If they can take in energy, then they can also release energy.
And again, this is only one technique among many. And it may not suit everyone all the time.
Oh and what does this have to do with empathic perspective? Well think about it. We consider ourselves sponges of all emotions and types of energy. But if you flip the coin, changing your perspective of the same situation, you can also rid yourself of those emotions very easily.