Ofcourse you can! There is nothing stopping you... but you should know a few facts. In India soap nuts are mainly of two kinds.

The Himalayan variety – Sapindus mukorossi

The South Indian variety – Sapindus trifoliatus

The South Indian variety contains about 2-4% saponin whereas what Daily Dump is procuring and packing is the Himalayan variety (Sapindus mukorossi) that produces the most consistent quality of 10-14% saponin and is therefore more suited for laundry/washing.

The South Indian variety is more suited for medicinal purposes.
There is a visible difference in their washing ability. Also even if one were to use the South Indian variety (thinking it would be more economical), the cost would actually be much higher since the amount needed per wash is more.