The usual bugs on potted succulent plants are mealy bugs, which are white and fuzzy, and scale, which are like bumps, usually brown. A spray bottle containing 50% isopropyl alcohol (do you call it "surgical spirit" in the UK?) and 50% water, or even 100% isopropyl alcohol or ethanol, sprayed on the plant once a day for a few days (you need to kill off any eggs as well as the current bugs) is what most people do. I keep a spray bottle around and hit pests as soon as I see them, before they become a serious problem.

The brown spots on the Kalanchoe, could that be mechanical (impact) damage of some sort?

Thanks hoovb.

If only I saw your reply (did not receive any notifications from houzz) earlier. No wonder I couldn't find any isopropyl alcohol in various stores here because they're called surgical spirits. Pardon me, I just moved from a city where isopropyl alcohol is what I've known it as. I'll go get some surgical spirit tomorrow and eradicate those annoying bugs.

The kalanchoe comes from a cutting of another which is infected so to err on the safe side, I may just spray it. Thank you once again.