What is a good cleaning agent for components

And for metal surfaces a perfect cleaner is neoblank -- used exceedingly spaingly, cleans the surface with no residue and no risk of marking -- this is a huge quantity (75cl) -- can be found in 50ml packs which will last you for ever
https://www.amazon.com/Neoblank-Stainless-Steel-Lubricant-Neodisher/dp/B01MYLK4EV

neoblank is <10% alcohol and 30% mineral oil -- used in minute quantities it is safe for lettering (I found it as Liebherr supplies it with all their fridges)

For perspex and other plastic surfaces a cleaner like Ultra Lite is ideal
https://www.g-collective.com/print-supplies/standard_products/ultra-lite-glass-plastic-cleaner-mini