Reddit mentions of Skincare Redex Udderly Smooth Chamois Cream

The best chamois cream I found is Udderly Smooth (https://www.amazon.co.uk/Udderly-Smooth-Chamois-Chaffing-Butter/dp/B002DR4ISI)

Used it on my 100+ mile charity ride and didn't have any issues with saddle sores.

Ugh. Sorry if I'm getting a little bit frustrated with this, but you're really not stating your problem clearly here. If you describe what effect you're after in more detail, and what purpose the cream serves, it would be a lot easier to point you to something.
So far I gather : you need to prevent dryness, add moisture if possible, and prevent it from feeling unpleasant when rubbing against fabric. Sounds like an occlusive / anti-chafing gel more than a moisturizer.

Here is a really good product that's specifically designed for women's parts. I have it at home and it's really great for making the skin feel smooth and comfortable, and retaining moisture : https://www.amazon.com/MONISTAT-Complete-Chafing-Relief-Powder/dp/B00AXVJF52/

In the UK specifically, searching for "anti-chafing gel", there seem to be a couple of options :
Lanacane : I've had this one before and it's not as smooth / silky as the Monistat one, but it's ok.
https://www.amazon.co.uk/Lanacane-3284726-Anti-Chafing-Gel-28grams/dp/B00YCQGRJG

These two - I have no idea if they're good but have good reviews and the first one has suitable ingredients :
https://www.amazon.co.uk/Udderly-Smooth-Chamois-Chaffing-Butter/dp/B002DR4ISI
https://www.amazon.co.uk/Bodyglide-AB4-Anti-Chafe-0-45oz/dp/B000KIMTCY


Won't recommend you DIY this because it has more complex ingredients that you'll need to source and figure out how to assemble.