Systemic spray recommendations for scale on indoor citrus

[SecondaryPlans]

I've been battling scale insects on some indoor citrus plants for 2 years. After having spent waaaaay too much time wiping all leaves and stems individually, just to have it come back repeatedly, I have finally given up on controlling it this way. Life is just too short! I was somewhat happy to see I'm not alone when I saw this thread: www.mumsnet.com/talk/gardening/5057748-to-give-up-on-citrus-plants

But I love having little citrus trees, so I'd like to give it one last try with a systemic pesticide. If it's possible to get one that makes it safe to have the fruit, that's a bonus, but realistically there's little chance we'd ever consume any of them so happy to just go with the most efficient to get healthy plants.

Currently considering these:
www.amazon.co.uk/BugClearTM-Killer-Flowers-Fruits-Vegetables/dp/B00B2KO1JS
www.amazon.co.uk/Provanto-Smart-Killer-Action-Green/dp/B08QZCZCXW

Does anyone have any success stories with those or anything else?

Savon noir is fairly effective and not really toxic. It suffocates the insects. They hide in hard to reach places though so you have to do it a few times. The same will probably be true of pesticides

I've had three bay trees, well bushes really as they never get big enough to be called trees. They all succumbed to scale insect, despite wiping the wee b***s off regularly with soapy water, so I can only commiserate about your lovely citrus 💐

I have heard that overwatering makes some plants susceptible to scale insects. Citrus are even more prone to overwatering. I would try keeping them on the dry side to see if that helps.

There are other things that help to stop the roots being in wet soil. Ceramic pot. Don't repot them until absolutely necessary. Broken crocks in bottom of pot to help drainage. Grit or sharp sand mixed in with compost to aid drainage.

Then there's the whole acid loving thing to help keep them healthy.

Thanks for the commiserations and the tips! I'll keep in mind the overwatering - always a good reminder. I was so overwhelmed with the scale constantly coming back that I'd sort of forgotten about the basics.

Regarding the Savon Noir, I'm after something that doesn't rely on spraying (or wiping off) each insect anymore. My understanding is that the systemic pesticide gets into the plant, so the scale insects then absorb it as they feed on the sap. You don't have to make sure you spray every last one in every nook and cranny, which should hopefully make it less work (and more effective). I was just wondering if anyone had recommendations of specific ones that had actually worked for them.

@SecondaryPlans, as far as I am aware, there is only one systemic insecticide which can be watered in as a drench, which is Bug Clear Ultra Vine Weevil Killer. It does claim to kill scale. It is quite expensive at around £14 a bottle of 480 mils, and the dosage is 60 mils in one litre ( one bottle will make up an 8 litre bucket). I do use this in my greenhouse for control of mealy bugs, and it is reasonably successful, but no experience with scale.

Have you not used Methylated spirits and spot cleaned them off, it works well with scale and mealy bug... although the chemist did ask me what I wanted it for!