I'm a BIG fan of using water to cleanse my crystals, especially new ones. Water is one of the four elements and it's what we use to cleanse ourselves. I mean, it's powerful enough to create the Grand Canyon!
Remember: intention is key so if you don't have access to fresh, natural running water it's okay. I live in the desert. I feel your pain.
You can dip your crystals into a natural body of water. I went into the mountains to Prescott, AZ for my 42nd birthday and treated myself to some new crystals on my birthday. On the way home I stopped at Montezuma's Well and hot springs and dipped my new crystals into that amazing water. I looked cute walking around with my bulging pockets...that were then also a little wet.
I have also bottled ocean water from California to bring home and water from the Salt River way up in the middle of nowhere a couple hour drive from where people use that river for recreation. I then put the water in a bowl and dip my crystals into it. You can also transfer this water to a spray bottle to mist your crystals.
I left my crystals out for the Full Moon during a Monsoon storm once. That was especially fun!
One thing I haven't tried that's popular is to make moon water. So you put water into a glass jar and leave that out in the full moon to charge. You can use that water to dip or spray your crystals.
And I have no problem whatsoever using tap water. I fully believe that rituals are 98% intention and can achieve the desired results without the pomp and circumstance.
Cleanse new stones to help them shed any energy they picked up in the supply chain. Cleanse stones before and/or after a particularly toxic person has been in their space. And cleanse them occasionally of the things they pick up while helping you.