Dear Dreamorph ,
Do you have to go to Seacon for shopping or something next time ???
If you are near Seacon , it would be easier to go to THE DOOR .
Just take an air-con 145 bus (very frequent , and 24 hour operated )
Bus 145 goes along Si Nakarin Rd , cross railway ( Hua Mak ),
then Ramkamhean RD to Bang Kapi .
Get off about 4 or 5 bus stops after The Mall Bang Kapi .
I hope it wouldn't take as much as you coming from the city centre .
By the way , BKK all local saunas are KAO NIOW MAK MAK .