If you use the home machine as a SOCKS proxy, you don't need Squid. Make the proxy connection and then configure your browser to use the SOCKS proxy at the localhost.
Then as long as that connection is open, you can use the SOCKS proxy via that port on the localhost. Be sure that DNS queries are also going via the proxy. Go to the URL about:config and set network.proxy.socks_remote_dns to true.
ssh -D 12345 home.example.org
If you want to use Squid, don't use the SOCKS proxy. Instead, make a tunnel to Squid and configure your browser to use the regular proxy at the designated port on the localhost.
You're using Firefox, right?
ssh -L 3128:localhost:3128 home.example.org