I believe Nikwax cleaning solution will restore waterproofing. There's a cleaning solution and a "conditioner" of sort....Google it and it will lead you step by step.
Also, I recently purchase a spray called Tarrago Nano to renew a waterproofing on my boots. On the spray it said it was good for jackets too.Google it or check it out on YouTube.
I'm pretty sure Nikwax is a proven product, on the market for years. I have the same Firstgear Kilimanjaro, I washed it with Nikwax and it is still waterproof.
Not sure about Tarrago spray, looks like it's working but haven't checked it out yet.
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