How can I run Minecraft through a proxy?

I have a socks proxy available on my local machine, which is set up using putty to SSH into a remote box I have access to.

I want to run Minecraft using this proxy, as there are firewall rules in place for security reasons at my current place of living. This type of use is not against policy, however.

I have tried running the game using varients of this command:

java -DsocksProxyHost=127.0.0.1 -DsocksProxyPort=8080 -Xmx800m -jar Minecraft.exe

And also this one, run from within .minecraft:

java -DsocksProxyHost=127.0.0.1 -DsocksProxyPort=8080 -Xmx800m -jar launcher.jar

These are successful (I believe) in running the launcher through a proxy, but not the game itself (multiplayer).

I have tried running the game from the technic launcher instead, passing the proxy parameters as java args, but this has no apparent effect. I have also tried using the Java Control Panel to set a proxy for the JRE, but this has no noticeable effect.

What am I missing?

Apologies if this is a duplicate. There are several other questions of this nature, but I think the solutions offered no longer work.

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