I can really only speak for my own work based off of client feedback, but Goddess locs and faux locs can generally last 2-5 months . On average these locs last about 12 weeks. Depending on the person, the care put into the preservation, and the technique of the installation they could even last longer.
The longest I have known a client of mine to keep their locs in for was about 5 and a 1/2 months with 1 touch up. The longest I have ever kept mine in was about 4 months, and yes i washed them. I even created a post titled how to properly wash your faux locs and goddess locs.
Personally I do not recommend keeping your locs in longer then 5 months at a time. I know everybody is different but some of you might not want your real hair to actually start to loc so take them out before that occurs.
I have resources on my site if your wondering how do i take out my goddess locs or faux locs ? The proper way. And even though this styles actually looks and feels better over time remind yourself it is not okay leave them in too long , this hair is not yours you will need to take them out. If you want to keep them consult your stylist as there are permanent alternatives.
In order to keep your locs looking amazing for longer I always provide my clients with proper care instructions for optimal maintenance. I also have a post titled how to maintain my goddess locs or faux locs and it's a short informative read.
Im happy to answer any and all inquiries, to book your next install with me click here <-