Hi all!

I was thinking about using PS as a paint cleanser before sealing the car with Opti-Seal: is it worth it?. I will be applying it by hand as I don't have access to DA and don't expect any correction, just want to clean the paint.

If so, what applicator to use?, any good advise previous to use?.

Best regards from Spain

Poli-Seal followed by Opti-Seal is a combination I use quite often.
I happen to use a PC and a polishing pad with the Poli-Seal, but I would think a foam applicator pad would work good for hand application.
Here's a link describing hand application.
Poli-Seal By Hand

Thanks Charles, very much appreciated info. Any chance of inducing marring applying PS by hand with orange side of this German Polish applicator you could think of?.

Best regards form Spain.

The pad you refer to is not one I have used, but since it is described as a "light cutting" pad, there is a possibility it migh leave some marring. Any marring would be from the pad, not the Poli-Seal.
You could do a test spot to find out before you do a large area of the vehicle.

As OPS is formulated for machine use, you won't have optimal results with it in terms of correction and cleaning. However you are going to utilize Poli Seal's protective and optical qualities.

Poli Seal is an excellent chemical/mildly abrasive cleaner, but you'll need at least a DA to fully exploit its abilities. I'm sure that in Spain lots of cheap random orbit sanders, aka DA polishers are available in the hardware stores. Think of Brico Store, OBI, Praktiker etc.

If you work strictly by hand, use a very soft applicator and a bit of pressure. Microfiber apps are excellent, but you can use a finishing pad as an applicator too.

Thanks to both, I'm sure I will achieve good results as always with Optimum products.

Best regards from the not-so-sunny-now Spain.