You could read the information on your winter wash (but probably too generic, so a "it is possible that").
It depends also on the type of bricks (usually they are clay, so never put acid stuffs on them).
Bricks are often porous: you may notice it, that wet brick (rain) are usually much darker. Oil will just attach on them, and it is difficult (and it takes also times), before the colour return normal).
As in the first point, you may notice that most "pesticides" doesn't recommend to be used near artefacts (and often near other vegetables: varieties and species not specifically listed).
You have few choices: try with water (a lot, and stark), racks all leaves regularly. Pruning could also help. If you have similar plants, or other plants with aphids, do winter wash on them. This will reduce the problem. So in addition, you need one of these things:
You could use (in vegetative state) some systematic pesticide: it will enter in the sap, and sap will distribute on all parts. Just a warning: do not burn the leaves. Maybe you should do in several days (so that you have all dose, but given only on easy accessible part of the plant). [Or some biological methods: you may be able to buy ladybugs or other aphid killers]
I saw also some gardener using a paint brush. It may be practical for small plants (or after a heavy pruning).
Sap is also a method. Like oil has some surface tension which may kill eggs, but sap works on aphids also on vegetative state (unlike winter oils). But also in this case you may have problem with bricks (much more seldom). Try on a place where nobody notice it (so usually on bottom part of a wall)