No this will not work at all! They may be called slugs - but are small larvae of sawflies. If you do not have time to inspect the underside of the leaves and squish those you find - you can spray with a real insecticidal soap - or the organic insexticide pyrethrum. I prefer the latter - it is sold in USA under names like: BonideÂs Japanese Beetle Killer. Be careful to spray the underside of the leaves as well as from above. The "slugs" look like this:

A few details of the history of the problem -- what happened, when -- and what you did to fix it, might have helped obtain a response or two.

Well, first off, it's an Adenium, like Michael said. It's a member of the Apocynaceae family, like Plumeria and Oleander/Nerium. Water is probably not the problem. The branches probably were damaged by the cold. If it was exposed to freezing temperatures for an extended time, that might be the problem. See how your leaves are drooping, but still green? Plants don't do that when they get dehydrated. They suck water and nutrients out of the leaf, leaving it yellow and withered before it drops off. That tells me it's probably a reaction to the cold exposure. Check the caudex (the swollen trunk at the base of the plant). If it is still firm, it probably isn't too damaged. I would also unpot it and check the swollen roots beneath the soil. If they don't show signs of rot, then you're probably safe, although it wouldn't hurt to apply some anti-fungal. If isn't firm, you can look up a course of action. Some people will cut the dead parts out, it's a pretty drastic operation and I'm not an expert on that, since I've never had to deal with it. Luckily, if it does survive, adeniums are absurdly hardy. They don't like cold or rot, but they will tolerate unbelievable amounts of physical mutilation. You'll probably loose the branches from where the withering is and above. Cut them off if they don't recover and you notice the withering spreading downwards. That will let the adenium form a callus. Careful, the sap is poisonous, like plumeria sap. Don't sweat the branches; adeniums usually get pruned down to about that level when they get as leggy as yours. Be careful with the watering, it might stay dormant all winter, and you shouldn't let it go completely without water, but you don't want it to rot either. Maybe give it a little water once or twice a month, it really depends on the potting medium.

Your irises look great! What I see is a little leaf spot.. Not a lot and not enough to worry about. Just take your clippers and cut back the fans that have the spots if you want to. . Leaf spot lives in the soil.. Hot wet humid conditions is what brings it on.. It will not hurt your irises it will just make them ugly.. The outer leaves also usually brown and die back this time of year as well.. You can treat with a fungicide but its not necessary.