Castile Soap is named after Castile, Spain a region that is known for its olive oil. The castile bar of soap was traditionally made with animal fat or olive oil but is now produced with different vegetable oils like palm, coconut, hemp, jojoba and olive.
Castile soap is quite the travel life-saver as it is not only eco-friendly, it is free from artificial foaming agents and harsh cleansers while also being biodegradable, but it is also a truly a versatile product that can replace many common staples in any travel beauty bag.
There are many different companies that sell Castile Soap (Kiss My Face & Mountain Skye) or you can make your own, but it seems the most popular and widely available (I’ve often seen them in Whole Food Stores and Planet Organic in my city) is Dr. Brommer’s Castile Soap. Dr. Brommer’s castile soaps boast more than 18 different uses including toothpaste, household cleaner, shampoo and cleanser.
4ee4f95981373ce0c072dbbb4f13baf5Dr. Bronner castile soaps
The line (which is certified organic) has a huge variety of Castile soaps in an assortment of scents, including an unscented version. But the secret to unlocking their potential is understanding when to (or not to) dilute the soap in water to obtain the desired effect. I recently switched from shampoo to no ‘poo and although I have hit a couple of bumps in the road I’ve noticed that sometimes the solution to a hair problem is as simple as fiddling around with the ratios. I would recommend doing the same thing with any castile soap if you hit a road block.
For example when used as a cleanser many individuals maybe feel that application of the soap straight to their skin may cause drying. The soap is made from organic saponified oils and can be diluted (half and half) to form a gentle lather that will effectively clean anyone’s face. Other uses for travel purposes can include (dilution tips taken from Going Green with a Bronner Mom and Her Packing List):
Shaving: Face – 10 drops; Underarms – 3 drops; Legs – ½ tsp; Work to a lather in wet hands and then apply to area.
Body: one small squirt on a wet washcloth, applied to a wet body
Foot Bath: 1 ½ tsp. in a small tub of hot water.
Laundry: 1/3-1/2 c. of soap for a large load in a normal washer. Add ½ c. vinegar to the rinse cycle. Use half of these amounts for HE
After shave: Dab a few drops on and it won’t burn like many aftershaves.
Cooling lotion: The peppermint and eucalyptus varieties can be rubbed on for a cooling sensation.
Hair: ½ Tbsp. in your hand, worked into wet hair, or dilute ½ Tbsp. in ½ a cup of water and work that into wet hair. To counteract any drying effects of the soap, I would also recommend rubbing a very small amount of oil (coconut, oil etc.) onto the ends of towel dried hair.  
What is rule numero uno when packing? Less is more. Dr. Bronner’s Castile soap is eco-friendly, fair trade, certified organic and sold in recycled bottlesPLUS a multi purpose travel essential that covers a huge variety of traveling needs and lasts for months. It is also sold in many countries around the world (just in case you run out) and come in a variety of sizes. It is quite literally one of the most travel-savvy products that one can pack on their next trip! 
Please note that this is not a sponsered post and is a personal opinion.